Hello all. I am wanting to convert my road bike, which was once converted to a single speed, now into a three speed (just recently purchased a dedicated single speed). Is it possible to use a front three speed shifter together with a rear derailluer or is the spacing of the rear cogs way off? If I need to use a rear shifter with the rear derailluer, what is the best way to set the limits? Thanks for the help.

If you're going for an externally geared hub I fail to see the point in limiting yourself to 3-speed. That'd either mean building up a custom cassette by stripping a stock one down and adding spacers, or riding around with a bunch of sprockets that'll never see any use.
Technically it should be easy enough simply to turn the limit screws way in, so that the stroke of the RD only covers 3 sprockets. I can imagine that you'll have to get some longer screws though. If the limit screws aren't enough you should be able to create a crude stop by threading the shifter cable through an electric terminal somewhere where the cable is exposed. Screw the terminal down on the cable so that it fetches up against a cable clamp on the frame and you'll have a functioning stroke limiter.

Also, if you're only running 3-speed but on external gears a friction shifter should do just fine. Haven't heard anything about how much a RD would move when hooked up to front shifter. OTOH if you're set on building a custom cassette it shouldn't be too hard to tinker around with spacers until you get a spacing that'll line up with the movement of the RD.

But if you're set on 3-speed, why not an IGH? doesn't take too much to make those play nice with just about any shifter with sufficent stroke.

Another way to consider.

tcs

I've actually done this once before. It works. The rear derailer was used only as a chain tensioning device. The stop screws were set such that it was aligned with the teeth on the SS freewheel. This is a somewhat inelegant solution. You still need two derailers, or some kind of chain tensioner. And the chain shifts under higher tension of pedalling, if that is an issue with you. I think a three speed cluster at the rear makes a little more practical sense. It's easily done and customized with cassette cogs, only one derailer is needed (rear), and the chain shifts under consistently lower tension of the derailer.

Three speed hub is an alternative. Utilizing one may solve some problems, create others, depending on your needs.

The idea of a three speed cassette sounds interesting to me. Why three speed cassette? Has all the range I need, with lower maintenance of a single derailer, modest hardware demands, and ease of customability.

OH he wants to use the derailluer like this? forget the 3spd go NEXUS 8!

Thanks for the replies everyone. I'll look into the tips mentioned.

I'm not too fond of 3-speeds, but then my knees are crybabies. 3-speeds just haven't got the ratios that I need to be able to ride comfortably. One thing I've thought of trying is a version of half-step gearing though. If it'd be possible to fit a close ratio quad up front a 3-speed IGH could give you 12 gears very evenly spaced.

It doesn't make sense to me to add a rear derailleur / chain tensioner and a front derailleur to achieve three speeds using chainrings. Makes a lot more sense to keep a cassette and eliminate the front derailleur, for more speeds and fewer components.

Dannihilator has a 3 speed you describe. One chainring, and 3 cogs on a 8/9/10 speed hub with a spacer.

Do you know if he uses a rear shifter or managed to figure a way to use a front 3 speed shifter?...